Post by profIJMJust wondering.
A really easy way to gather data on people and advertise to them, disguised as a way to keep in touch with everyone you've ever known regardless of whether you actually like them. It's also a way to stalk people, waste time looking at pictures of your coworkers' babies, show off pictures of yourself drunk, share your racist and/or homophobic opinions with the world, and Like stuff (because before Facebook nobody had invented a way for people to like things).
Before Facebook, people just phoned or emailed each other, or (GASP!) spoke to each other in person. It was back in those golden days that people would spray their latest thoughts on the front of their houses, and other people would come along and spray "Like" next to it. We would also mail photos of ourselves drunk to everyone we've ever met, along with photos of our babies if we had any. We would also track down everyone we've ever known and force them to be friends with us. If they agreed, they would immediately have access to all our photo albums, all our thoughts on everything, contact details of everyone else we've ever known, and see a list of everywhere we've worked. I can remember thinking at the time, "I wish there was one thing that made all of this absurd over-sharing much easier".
;-D
Ed the Cat